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M51 Sc Stack 149frames 1490s g450 clipped

M51 Sc Stack 149frames 1490s g450 clipped

24.8 minute EAA view

Celestron 8" SCT, Night Owl reducer, F/4.23
ASI2600mc pro, 450gain, -10C, 10s subs, darks, no flats
SharpCap 4.1

The SCT and AT115EDT imaged M51 a couple of days apart.
Comparing these views

  • Seeing (FWHM corrected for pixel scale) is almost identical for both scopes, so both images are seeing limited and the same sky limited resolution.
  • Both use Color correction enhancement
  • The SCT is faster and had more time on target - this is readily apparent by the improved S/N on the SCT EAA view. This provides better and more resolved S/N improved details in the view.
  • Stretch (6 for 115, 4 for SCT) has a noticeable effect on how the M51 looks in each view. This impacts the center detail in M51 where the 115 stretch shows more of the center of the galaxy, and the 115 stretch shows tighter stars. Both of these differences are a function of the different stretch functions used on the 2 views.

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